A debugging procedure for finding the underlying cause of bugs, failed commands, crashes, and unexpected behavior. It checks project memory, error details, timing, and the relevant specialist guidance before changing code.

Use it when investigating errors in backend code, interfaces, databases, or security-sensitive behavior, especially when logs or recent changes need to be examined.

It helps avoid fixing only the visible symptom and preserves the discovered cause, fix, affected files, and remaining risks for later work.

debug — Cursor rule for Cursor by VoTruongDanh/Skills-Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo

git clone --depth 1 https://github.com/VoTruongDanh/Skills-Agent

Made for: Cursor.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/rules/votruongdanh/skills-agent/debug/github.svg)](https://agentmods.dev/rules/votruongdanh/skills-agent/debug)

Your own site

<a href="https://agentmods.dev/rules/votruongdanh/skills-agent/debug"><img src="https://agentmods.dev/badge/rules/votruongdanh/skills-agent/debug/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/rules/votruongdanh/skills-agent/debug"><img src="https://agentmods.dev/badge/rules/votruongdanh/skills-agent/debug.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 53 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.

When invoked 963 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00053	$0.00963
Opus 5.5	$0.00021	$0.00385
Sonnet 5.5	$0.00011	$0.00193
Haiku 4.5	$0.00005	$0.00096

Measured 1mo ago against content hash f708f624cca6, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

debug scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/debug.mdc · 82 lines

How it starts

The opening of the file, as written. The whole thing — 82 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Memory Protocol

START: Read .ai-memory.md from project root. Check for known bugs, past fixes, tech stack details, common error patterns, and architecture notes. END: Update .ai-memory.md using Memory Compaction Rules with: bug, root cause, fix, files touched, lessons learned, and remaining risks.

Goal

Find the real root cause, not just the first visible symptom.

Agent Routing

If bug is in API/server/backend → read .kiro/skills/agents/agents/backend-specialist.md and apply its knowledge
If bug is in UI/rendering/CSS → read .kiro/skills/agents/agents/frontend-specialist.md and apply its knowledge
If bug is in database/queries → read .kiro/skills/agents/agents/database-architect.md and apply its knowledge
If bug may be a security issue → read .kiro/skills/agents/agents/security-auditor.md and apply its knowledge
Default → read .kiro/skills/agents/agents/debugger.md and apply its systematic analysis

Socratic Gate

Before debugging, verify:

What is the expected behavior vs actual behavior?
Is there a log, stacktrace, or error message?
When did this start? (recent change, always broken, intermittent?)
Have we tried this before? If any answer is missing, ASK before proceeding.

Workflow

Read Memory — Load .ai-memory.md for project context and past bug history.
Summarize the bug, expected behavior, and actual behavior.
Gather evidence from logs, stack traces, code paths, config, and recent changes.
List the top hypotheses ranked by likelihood. Eliminate previously failed hypotheses immediately.
Eliminate hypotheses using direct evidence.
Identify the root cause and confirm with evidence before attempting any code changes.
Propose an effective solution that addresses the root cause definitively. Ensure clean code standards are met and fully update all related files.
Suggest how to verify the fix and prevent regressions.
Quality Gate — Read .kiro/skills/_scripts/checklist.md and run cross-cutting quality checks.
Update Memory — Save root cause, fix, and lessons to .ai-memory.md.

Read the full file on GitHub · 82 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

1mo ago Changed · +3 lines f708f624cca6
1mo ago First seen · 79 lines · 53 tokens per session scan A e46680c3b149

Subscribe to this mod's changes

debug is a cursor rule published in the GitHub repository VoTruongDanh/Skills-Agent (4 stars, last pushed 18d ago), licensed MIT. It adds 53 tokens to every session and 963 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Debugging

error-handling-and-validation

A code-quality guide for handling errors, invalid inputs, edge cases, preconditions, logging, and user-friendly error messages.

holtwood/awesome-cursorrules-zh · 185 tokens

css-render-blocking-diagnosis

Cursor rule "css-render-blocking-diagnosis" from adobecom/da-express-milo, covering css render-blocking diagnosis & resolution, critical learning from 98 pagespeed achievement, primary diagnostic protocol, step 1: css blocking symptom recognition and step 2: css loading sequence audit.

adobecom/da-express-milo · 1,102 tokens

debug